海岛矿区岩质边坡植物群落演替中物种多样性的变化

通过植物群落调查,采用Shannon多样性指数、Simpson优势度指数、Margalef丰富度指数和Pielou均匀度指数,结合DCA排序和一元线性回归分析,考察了舟山海岛矿区岩质边坡植物物种构成特征,研究了植物群落演替过程中生物多样性的变化。结果表明:研究区可划分为3个植物群落演替阶段(草本植物群落阶段、灌丛群落阶段和灌乔群落阶段);演替过程中,物种丰富度指数显著上升,多样性指数和优势度指数逐渐升高;具有矿区特殊生境适应性的植物配置在边坡植被恢复进程中与自然植被表现出一定的差异,演替过程依次为迁入物种生长期、迁入物种与人工导入种竞争期、迁入物种与人工导入种稳定共存期;人工导入群落演替后期的植物种大大加速了群落演替进程;合理的植物配置更能促进群落向正演替方向发展。     

库姆塔格沙漠南缘荒漠植物群落多样性分析

 根据20个样地的调查资料,应用重要值计算多样性指数、均匀度指数、丰富度指数 、优势度指数,对库姆塔格沙漠南缘荒漠植物群落物种多样性进行分析。结果表明: 1）荒漠植物群落分布随其生境地貌不同而不同,山前戈壁上分布有合头草(Sympegma regelii)群落,冲积河道低地分布有荒漠林胡杨(Populus euphratica)、多枝柽柳(Tamarix ramosissima)、胀果甘草（Glycyrrhiza inflata）群落,戈壁沙漠过渡带为梭梭(Haloxylon ammodendron)群落,低海拔的沙山上分布有沙拐枣(Calligonum mongolicum)群落、膜果麻黄(Ephedra rzewalskii)群落和梭梭群落。2）荒漠植物群落物种多样性水平较低,群落结构简单,物种组成单一。群落Shannon_Wiener物种多样性水平表现为合头草群落最高（1.706）,具有草原化荒漠植被类型的成分;梭梭群落、膜果麻黄群落居中（0.875～0.890）,荒漠植被类型特征明显;沙拐枣群落、胡杨群落、多枝 柽柳群落、胀果甘草群落较低（0.079～0.495）,荒漠林、盐地沙生灌丛及盐化草甸植被均有零星分布。3）荒漠植物群落结构层次中,灌木层占居主导地位,群落灌木层物种多样性水平（0.769～1.451）远远大于草本层（0.193～0.254）,且草本层物种多样性受灌木层影响较大。4）荒漠植物群落物种多样性分布格局表现为经向、纬向和海拔梯度的变化,经向、纬向变化为物种多样性水平较高的草原化植物合头草群落（1.706）向物种多样性水平较低的荒漠植物梭梭群落（1.379）和盐化植物多枝柽柳群落（0.376）的过渡,海拔梯度则 呈现低水平的沙拐枣群落（0.819）到高水平的膜果麻黄群落（0.890）向低水平的梭梭群落 （0.645）变化。荒漠植物群落过渡地带一般具有较高的物种多样性和较低的生态优势度。     

管涔山撂荒地植物群落演替过程中物种多样性研究

用TWINSPAN分类方法将管涔山撂荒地植物群落的演替过程划分为7群丛,分别属于植被演替的3个阶段--草本群落阶段、灌丛群落阶段和森林群落阶段.用物种多样性指数分析了物种丰富度、均匀度、多样性和优势度的变化规律,结果表明,随着演替时间的延长,物种丰富度和多样性有增加的趋势,优势度、均匀度有降低的趋势.用DCA排序分析植物群落的结构、组成和生活型在演替过程中的变化规律,表明随着群落环境条件的改善,群落内物种的组成发生了很明显的变化,最后发展为适应该区域环境条件的、以华北落叶松为建群种的、稳定的群落,结果显示群落内物种组成愈丰富,则多样性愈大.进一步用DCA排序分析物种多样性与海拔和时间之间的关系,表明随着海拔的升高和时间的延长,结论和前面一致--物种丰富度和多样性逐渐增加,优势度、均匀度逐渐降低.     

松嫩平原破碎化羊草草甸退化演替系列植物多样性的空间格局

物种多样性格局是国际生物多样性科学前沿领域热点问题.本文以松嫩平原破碎化羊草草甸退化演替系列(6种植物群落、144个斑块)为研究对象,系统地探讨了其α、β和γ多样性空间格局及其机理.结果表明:在羊草草甸退化演替系列中共发现87种植物,但没有一种能分布于所有斑块;羊草+鸡儿肠群落或羊草群落的α、β和γ多样性较高,多稀有种和特有种;碱地肤群落最低,少稀有种,无特有种;γ多样性与α多样性显著正相关,但与β多样性无相关性.各植物群落的α多样性与单个斑块面积呈显著幂函数关系,β多样性(相似性指数Sjk)仅羊草+鸡儿肠群落呈显著幂函数关系;斑块平均面积和总面积与α、γ多样性呈显著正相关,与β多样性无相关性.群落的物种丰富度越高,稀有种和特有种就越多,物种在局域斑块上灭绝的可能性越大;β多样性在物种多样性格局中的重要性与生境破碎化程度有关.     

科尔沁沙地植被恢复系列上群落演替与物种多样性的恢复动态

通过对科尔沁沙地植被恢复系列上不同阶段的群落取样,研究了植被恢复过程中群落物种组成、物种多样性的变化过程.在演替时间分别为1年、3年、5年、12年、20年和30年的群落中,物种丰富度分别为7、11、17、14、28和30种,而物种多样性指数分别为1.458 8、2.610 0、3.108 4、1.696 8、3.738 6、3.639 6.在生活型结构上,一年生植物的种类数量占绝对优势,但随着演替进展,多年生植物的种类数量增加且单种植物的优势度超过了一年生植物,表明多年生植物在群落功能维持中占据重要地位.随演替进展,来自不同科属的植物增加.藜科植物在演替过程中种类数量较为稳定,特别是在演替早期藜科植物占有很高的优势度.禾本科种类随演替进展不断增加,且在群落中的优势度逐渐上升.总体上,随演替进展群落种类组成与物种多样性增加,群落生态优势度下降,而均匀度增加,群落趋向稳定.     

放牧干扰下若尔盖高原沼泽湿地植被种类组成及演替模式

以若尔盖高原退化沼泽植被为研究对象,应用多重比较、双因素方差分析、物种累积曲线、PCA排序、方差分解等方法分析了不同放牧压力、放牧季节下物种丰富度、多度、生活型组成、群落演替的变化。结果表明:不同放牧季节物种丰富度格局不尽相同,其中6、9、10月在各牧压梯度间无显著差异,7、8月均以极重度和极度阶段(中生草甸)的最高,原生沼泽的最低。在物种累积速率上,沿牧压梯度以极重度和极度阶段的最高,沿放牧季节以7、8月最高;双因素方差分析结果进一步表明物种丰富度与放牧季节无显著关系,但与放牧压力关系显著。放牧压力和放牧季节共解释了物种多度总方差的47.6%,其中放牧压力解释了50.1%,放牧季节以及二者方差交集均为负值;沿牧压梯度,沼泽植被逆向演替模式倾向于沼泽→草甸,沼泽化草甸阶段不明显,但是演替方向未发生变化,建群种替代规律为:乌拉草→木里苔草→栗褐苔草,生活型组成中直立型植物比例较少,莲座型和匍匐型植物增加。总之,放牧季节对物种丰富度无显著影响,但在一定程度上改变了其牧压梯度格局,降低了物种累积速率。放牧压力改变了群落物种丰富度、生活型组成和演替模式,但放牧可能仅为沼泽植物群落物种多样性格局和演替的驱动力之一。     

宁夏东部风沙区荒漠草原植物群落物种多样性研究

通过野外植被调查,研究了宁夏东部风沙区荒漠草原植物群落组成与结构、物种多样性变化;采用典范对应分析（CCA）对植物群落分布与土壤性状关系进行了分析。结果表明：（1）风沙区荒漠草原物种较为单一,多集中在6~13种;不同群落类型间地上生物量和盖度差异显著;群落内竞争性较弱的物种减少,优势种具有较高的重要值。（2）群落间物种多样性差异显著,但变化趋势并不一致;物种多样性指数与丰富度指数、均匀度指数的相关系数分别为0.975 7和0.880 2,而与优势度指数相关系数为-0.519 8。（3）CCA结果表明,土壤含水率、有机质以及氮磷钾含量较高、容重小时,植物物种相对丰富;对群落分布影响较大的环境因子是土壤水分、容重和土壤有机质,相关系数分别为-0.742 8、0.683 8、0.532 9,物种和群落二者在CCA排序轴相关性较大的土壤因子较为一致。研究认为,宁夏东部风沙区荒漠草原植物优势种在群落中的地位明显,物种丰富度对植物多样性的影响大于均匀度,土壤水分是影响该区草原植物群落分布的决定性环境因子。     

洪河自然保护区典型湿地植物群落组成及物种多样性梯度变化

以洪河自然保护区两类典型湿地——河漫滩湿地与碟形洼地湿地的植物群落为研究对象,探讨其物种组成及物种多样性的梯度变化规律。结果表明,由沼泽至岛状林的梯度上:(1)各群落建群种、优势种和伴生种的种类及其优势度,地表覆盖藓类等组成特征均变化明显;(2)群落的物种丰富度呈逐渐增加格局,丰富度指数分别为26、41、51、68和82;(3)群落的α多样性的变化格局与丰富度格局不太一致,Shannon-Wiener多样性与Pielou均匀度的变化格局基本一致,呈不规则"N"型格局,Simpson优势度的变化格局正好与它们相反,呈不规则倒"N"型格局;上述格局的两个"拐点"出现在沼泽化草甸群落和湿草甸群落中;(4)群落的β多样性——相异性系数和Cody指数均呈先降后升的格局,二者的最小值出现在沼泽化草甸群落和湿草甸群落之间,最大值出现在灌丛草甸和岛状林群落之间;研究认为,典型湿地植物群落物种组成和物种丰富度的梯度变化主要于生境的变化有关,α多样性的变化格局主要与生境的变化和优势种的生物学特性有关,β多样性的格局的原因比较复杂,尚需进一步探讨。     

新疆喀纳斯湖北端河漫滩湿地植物群落演替

对喀纳斯湖北端河漫滩湿地植物群落进行了调查取样,通过除趋势对应分析(detrended correspondence analysis,DCA)排序研究了群落演替的动态,同时采用Shannon多样性指数、Margalef丰富度指数、Simpson多样性指数和Pielou均匀度指数,分析了物种多样性在群落演替过程中的动态变化,并运用去势典范对应分析(detrended canonical correspondence analysis,DCCA)方法,分析了不同样方中土壤因子与群落多样性指数之间的关系。结果表明:1)该区域植物群落演替序列为泽生苔草群落→西伯利亚早熟禾群落→金露梅群落→沼桦群落→西伯利亚云杉群落;2)随着演替的进行,群落物种优势度显著增加,而物种多样性呈先增加后降低的趋势,金露梅群落最高;3)土壤含水量和群落物种优势度之间存在显著负相关。     

露天煤矿排土场边坡植被组成特征及其群落稳定性评价

研究植被恢复过程中植物群落组成、结构及稳定性的变化,可进一步了解到植物群落的演替过程及规律。采用空间代时间的方法对内蒙古锡林郭勒盟北电胜利露天煤矿4个排土场边坡人工恢复植被进行群落调查,在此基础上采用多样性指数与优化后的M.Godron稳定性指数对植物物种组成、物种多样性及其群落稳定性进行分析,探究不同恢复年限排土场边坡植被在恢复过程中群落特征及稳定性变化特征。结果表明：（1）排土场边坡植物物种组成共有16科44属56种,植物群落组成较简单,其中禾本科种类最多,生长型以草本植物为主。（2）随着恢复年限的增加,植物生活型由一、二年生转变为多年生,坡面优势种由人工种植植物转变为本土植物。（3）整体看,随着恢复年限增加,物种多样性呈下降趋势,群落稳定性整体呈上升趋势。（4）由于不同坡向土壤微环境差异,北坡恢复效果及稳定性好于南坡。本研究在一定程度上可为露天煤矿排土场边坡人工修复过程中植物物种及合理配置模式的选择提供科学依据。     

Plant Community Succession on Ant-hills of a Sub-alpine Meadow in Northwestern Sichuan,China: Species Composition and Diversity

Ants may increase habitat heterogeneity by means of building ant-hills, thereby changing community species composition and ecosystem structure and functioning. We investigated plant height, coverage and abundance for each species and calculated species richness and diversity for ant-hills of Camponotus herculeanus differing in size (309.45cm2, 948.45cm2, 2124.90cm2 for the small, intermediate and large ant-hills, respectively). The dominant species was subsequently identified for the three size-classes of ant-hills and the mechanism underlying anthill community succession was derived. Our results showed that diurnal temperature fluctuation was greater in ant-hills than the surrounding flat soil, where the temperature of the ant-hills was higher in daytime but lower at night relative to the counterpart. The soil moisture was lower in center than in edge of ant-hills whose moisture was lower than the flat soil. Plant species diversity and richness were not significantly different among the three classes of ant-hills while the dominant species conspicuously changed. The importance value of the most dominant species, Kobresia uncinoides, increased significantly with increasing ant-hill size; the subdominant species was Galium aparine, Festuca ovina, Elymus nutans for the small, intermediate and large ant-hills, respectively. The dominance of grasses was significantly higher, but that of forbs was lower on ant-hills than in surrounding communities. The ant-hills were dominated by species from Cyperaceae and Gramineae while Compositae and Ranunculaceae dominated the surrounding communities. In addition, we discussed the possible mechanisms driving ant-hill community succession and the potential significance of ant-hills to the whole community composition and dynamics in the alpine meadow.     

The roles of seed mass and persistent seed banks in gap colonisation in grassland

Gaps in grassland created by animals are often sites for species regeneration. The persistent seed banks of ant-hills and surrounding soils in a calcareous grassland in southern Britain were compared and analysed in terms of seed mass and longevity. The relative abundance of species on ant-hills compared to the pasture was highly correlated with seed abundance in ant-hill soil. The abundance of plant species on ant-hills compared to the pasture was significantly negatively correlated with seed mass, and positively correlated with seed longevity. These results suggest that germination from the seed bank in ant-hill soils, as well as limited seed dispersal and vegetative invasion, contributes to the distinctive ant-hill vegetation. The same may apply to other gaps created by animals in grasslands.     

The Effect of Hill-Building Activities of Ants on the Species Diversity of Plant Communitiesin Songnen Grassland 蚂蚁筑丘活动对松嫩草地植物群落多样性的影响

 吉林省长岭县羊草(Aneurolepidium chinense)草地自然保护区内分布的蚂蚁主要为玉米毛蚁(Lasius alienus)和黄墩蚁(Lasius flavus)。蚂蚁是草地生态系统的一个生物干扰因子。通过分析比较该保护区内4个植物群落中玉米毛蚁和黄墩蚁蚁丘上植物的种类组成、优势种的数量特征及群落多样性变化,探讨了蚂蚁筑丘活动对草地生态系统的影响。主要结论如下：1)蚁丘上的植物种类组成与对照显著不同。在蚁丘上分布的植物主要是羊草种组(Aneurolepidium chinense group     

Formation of springtail (Collembola) communities during colonization of ant-hills

Formation of springtail assemblages in resettled nests of the ant Formica aquilonia was studied. The species composition and relative abundance of springtails was shown to depend on the age, hydrothermal regime, and condition of the ant nest. The abundance and species diversity of springtails increases during the initial period of the ant-hill growth. Old nests are characterized by the minimum species diversity, with one or two distinct dominants. High ecological plasticity, including resistance to high temperatures and low humidity, allows Lepidocyrtus violaceus to maintain its stable dominant position in the ant-hills. Species with relatively narrow hygro-and thermopreferenda quickly occupy temporal favorable niches, reach high abundance, and quickly disappear as the microclimatic conditions change.     

The use of the mounds of Lasius fiavus in teaching some principles of ecological investigation

The mounds built by the yellow hill ant, Lasius fiavus, in British pastures have striking and consistent effects on the patterns of plant species. Winter annuals, for example, are often confined to the mounds, but many rosette perennials, though abundant in the surrounding grassland, are virtually absent from ant-hills. A comparison of the abundances of six or seven species on and off the mounds provides a field practical suitable for senior school students and undergraduates. The students discuss the sampling methods to be used, collect the data, analyse it, and discuss the factors which might influence the relative abundance of the plant species. This paper describes the practical in detail, and provides some background information about the ecology of the ants and some common grassland plants. Some suggestions for individual projects are put forward.     

Within‐year variation in the vegetative spread of five temperate grasses

Questions: Do species planted outdoors in native soil differ in the timing of their period of vegetative spread during the growing season? Location: Cleish Hills, Fife, Scotland, UK. Methods: Patches (20 cm × 20 cm) of Agrostis capillaris, Festuca rubra, Holcus lanatus, Lolium perenne and Poa trivialis were arranged in plots so that every species patch had all the remaining species as neighbours. The plots were cut every 14 days at 3 cm and photographed monthly from above. The photographs of species boundaries were traced and digitised. Measurements were made on the digitised images of the distances each species spread and of the area occupied by each species. Results: Fitting some simple models to the data indicated firstly that species varied in their vegetative competitive ability, with A. capillaris and P. trivialis being the most and least competitive respectively, and secondly that the ability of a species to colonize can differ from its ability to resist colonization, the most discrepant species being H. lanatus. Our analysis also indicated statistically significant variation in the data over and above the simple models, providing evidence of additional, genuine, complexity in the seasonal patterns of spread. Conclusion: This study provides evidence to support the hypothesis that clonal grass species do not spread vegetatively at the same times within a growing season. Since sward height is known to affect species spread, there is some opportunity for the manipulation of species composition simply through temporal control of sward height.     

海南岛霸王岭不同热带森林类型的种-个体关系

 比较分析了海南岛霸王岭自然保护区核心区热带低山雨林、山地雨林、云雾林、山地矮林等4种热带森林类型中不同大小径级树木的物种—个体关系。结果表明：各种植被类型中物种数与个体数对数成线性关系是一种普遍现象,且不受调查树木的径木级影响。在相同个体数的条件下,累积物种数随海拔增高而逐渐减少,也即物种数由热带低山雨林、山地雨林、云雾林到热带山地矮林逐渐减少。对于各种植被类型的种—多度关系,单个体、双个体的物种有相当高的比例,其后一般依个体数的增加,而逐渐降低物种的出现频率,呈典型的倒J型曲线,而且这一比例随树木径级的增加而增加。     

Exploring spatiotemporal patterns in early stages of primary succession on former lignite mining sites

Questions: 1. Does random colonization predominate in early stages of primary succession? 2. Do pioneer species facilitate the establishment of later arriving species? 3. Does an initially random distribution change to an aggregated pattern with ongoing succession? Location: Lignite mining region of Lower Lusatia, eastern Germany. Methods: Individual plants were mapped along a 2 m × 28 m transect during three successive years and classified into two groups (1) the pioneer Corynephorus canescens and (2)‘all other species’. Using the pair‐correlation function, univariate point pattern analysis was carried out by applying a heterogeneous Poisson process as null model. Bivariate analysis and a toroidal shift null model were applied to test for independence between the spatial patterns of the two groups separately for each year, as well by exploring spatiotemporal patterns from different years. Results: In the first year Corynephorus and ‘all other species’ showed an aggregated pattern on a spatial scale > 40 cm and in the second and third years a significant attraction for distances between 4 and 12 cm, with an increasing radius in the third year. The analyses of interspecific spatiotemporal dynamics revealed a change from independence to attraction between distances of 4 cm and 16 cm when using Corynephorus as focal species. However, applying ‘all other species’ as focal points results in a significant attraction at distances up to 60 cm in the first year and a diminishing attraction in the second and third years with distances ≤ 6 cm. Conclusions: Facilitative species‐species interactions are present in early stages of primary succession, resulting mainly from pioneer species acting as physical barriers and their ability to capture diaspores being drifted by secondary dispersal along the substrate surface. However, due to gradual establishment of perennial species and their ability of lateral extension by vegetative dispersal, facilitation may influence spatial pattern formation predominantly on short temporal and fine spatial scales.     

The diversity of 15 ha of lowland mixed dipterocarp forest, Central Kalimantan

Fifteen hectares of primary forest in Central Kalimantan were enumerated and all trees 10 cm dbh tagged and identified to species as far as possible. Tree density, relative abundance of families and species diversity were calculated, as was a mean additive species/area curve for 1 ha and a species/area curve for all 15 ha. The Jaccard index of similarity was also calculated for the 15 plots. The 15 ha enumerated contain 8771 trees with a dbh of 10 cm, belonging to 1298 morphospecies in 56 families. On average a single plot had 583 trees and 205 species. These figures are within the upper range of species diversity for the Malesian region as a whole. Dipterocarpaceae make up 14% of all trees in the plots, closely followed by Euphorbiaceae with 13%. A surprisingly low coefficient of similarity is found between the plots, the lowest being 3% and the highest 30%. Species/area curve construction showed that the asymptote is not reached in any of the 1 ha plots or when the 15 plots are added together.     

Habitat associations with topography and canopy structure of tree species in a tropical montane forest on Mount Kinabalu,Borneo

Habitat associations with topography and canopy structure of 42 abundant tree species were studied in a 2.74-ha plot of tropical montane forest on Mount Kinabalu, Borneo. Many of these species belong to the same higher taxa including eight families and four genera. Analysis of intraspecific spatial distributions for stems ≥ 10 cm diameter revealed that 28 species (including all six species of Fagaceae) showed aggregated distributions at the 100-m² and/or 400-m² scales, and that 20 species showed habitat associations with topography by torus-translation tests; 17 species showed both characteristics. Species' associations with the local canopy structure were characterized by crown position index (CPI), which was defined relative to neighbour trees. The CPI differed greatly among individual stems at 10–40 cm diameter, and 19 species showed significantly different frequencies of crowns exposed vertically versus those shaded beneath the canopy. Mean growth rates at 10–40 cm diameter and size distributions of species were not related to topographic associations, but were explained by the associations with canopy structure; species with more exposed crowns grew faster and had less positively skewed distributions. Diversity in habitat associations was manifest between two genera (Syzygium and Tristaniopsis) in the family Myrtaceae and among species in these genera, but was less evident in other families and two genera (Garcinia and Lithocarpus). This revised version was published online in June 2006 with corrections to the Cover Date.